Machine for splitting the ends of bars such as mine roof bolts



Dec. 27, 1955 A. B. HASWELL MACHINE FOR SPLITTING THE ENDS OF BARS SUCH AS MINE ROOF BOLTS 5 Sheets-Sheet 1 Filed Oct. 31 1951 h 1i: i f m m 5 e i M m I 5. m 1 y m w w m q 0 z I1 Ov .0 k K E 070%.) ,///.M Z J/ 7 M! H u E Z Z :n L I L E UN P z flew/0e B. Haw ELL,

Dec. 27, 1955 A. B. HASWELL MACHINE FOR SPLITTING THE ENDS OF BARS SUCH AS MINE ROOF BOLTS 5 Sheets-Sheet 2 Filed Oct. 31, 1951 Inventor: flew/0e 5. Haw 44, AW Aw fi/S fl/farng Dec. 27, 1955 A. B. HASWELL 2,728,090

MACHINE FOR SPLITTING THE ENDS OF BARS SUCH AS MINE ROOF BOLTS Filed Oct. 31 1951 5 Sheets-Sheet S 497%? 151 Haw 44,

Dec. 27, 1955 A, B. HASWELL MACHINE FOR SPLITTING THE ENDS OF BARS SUCH AS MINE ROOF BOLTS 5 Sheets-Sheet 4 Filed Oct. 51, 1951 Inventor: 44 7/7 09 5. Hafiz Va A, A

Dec. 27, 1955 A. B. HASWELL 2,728,090

MACHINE FOR SPLITTING THE ENDS OF BARS SUCH AS MINE ROOF BOLTS Filed ot. a1, 1951 5 Sheets- Sheet s FIEJE- F I E- 14-- erm/e 5 HQfl VELL,

"AmwA wa MACHINE FOR SPLITTING THE ENDS OF BARS SUCH AS NHNE ROOF BOLTS Arthur B. Haswell, Birmingham, Ala., assignor to United States Steel Corporation, a corporation of New Jersey Application October 31, 1951, Serial No. 254,179 6 Claims. (Cl. 11)

This invention relates to a machine and method for slitting the ends of elongated bars, particularly metal bars heated to temperatures at which they can be worked readily.

An object of the invention is to provide an improved machine and method for expeditiously and uniformly slitting the end portions of heated metal bars in a continuous operation and restoring the slit portions to approximately their orignial outside dimension.

A further object is to provide an improved bar slitting machine which has a plurality of cutting blades and means for automatically indexing the blades with each cut to present a cooled blade to each bar.

A further object is to provide an improved bar slitting machine which automatically feeds and clamps bars for slitting, automatically advances a cutting blade into the end portion of each bar thus clamped, automatically retracts the blade and ejects the bar, and automatically indexes the blade.

These and other objects will become more apparent after referring to the following specification and attached drawings, in which:

Figures 1 and 2 are side elevational views of a bar such as can be formed by the machine and method of the present invention;

Figures 3 and 4 are somewhat schematic plan views of plurality the clamping and cutting mechanisms embodied in the machine;

Figure 5 is a top plan view of the machine;

Figure 6 is a side elevational view of the machine;

Figure 7 is a side elevational view on a larger scale of the means for indexing the cutting blades;

Figures 8, 9, 10, 11 and 12 are vertical cross sectional views taken on the correspondingly designated lines on Figure 6;

Figure 13 is a sectional view taken on line )GII-XIII of Figure 12 and illustrating the indexing means with the guide removed to show more clearly the parts beneath; and

Figure 14 is a vertical sectional view taken on line XIVXIV of Figure 7.

Figures 1 and 2 illustrate a bar B, the end portion of which contains a diametric slit S like those produced by the machine and method of the present invention. Although the invention is not limited to bars slit for any particular purpose, one exemplary use for such bars is in supporting mine roofs. For this purpose a wedge W is inserted in the slit, after which the bar and wedge are driven into an opening R drilled upwardly from the roof. When the wedge abuts the closed end of the opening, it spreads the slit portion of the bar and thus anchors the bar. The lower end of the bar is screw-threaded and carries a washer and nut N for supporting the roof.

The machine of the present invention comprises a bedplate 10, a transverse crankshaft 12 mounted in bearings 13 and 14 on said bedplate, and a longitudinal camshaft 15 mounted in two outside bearings 16 and 17 and two intermediate bearings 18 and 19 on said bedplate. The

crankshaft is driven by any suitable motive means not in turn drives the camshaft at the same speed through suitable gearing 20. The bedplate carries a reciprocable crosshead 21 which the crankshaft drives through a connecting rod 22. This crosshead carries the bar guiding and cutting mechanisms. The bedplate 10 carries bar feeding, clamping and ejecting mechanisms all driven from the camshaft 15. Next I shall described in detail the feeding, clamping, ing mechanisms in that order, which is the order in which they operate.

Feeding mechanism The feeding mechanism includes a longitudinal feed shaft 25 mounted for rotation above the bedplate 10 in a of aligned bearings 26. The feed shaft carries a plurality of feeder plates 27, the configuration of which is shown in Figures 8 and 9. Each such plate has a plurality of radial bar receiving slots 28, in this instance eight in number.

The feed shaft 25 and its plates 27 are rotated in stepby-step fashion by the camshaft 15, which carries a feed cam 29 for producing such rotation (Figure 8). An upstanding lever 39 is pivotally connected at its lower end to the bedplate 10 and carries a roller 31 which engages the cam 29 and functions as a cam follower. A tension spring 32 extends between the bedplate and lever 30 to hold the roller in contact with the cam surface. A ratchet wheel 33 is fixed to the feed shaft and a ratchet housing 34 rotatably mounted thereon. The ratchet housing carlies a pawl 35 which engages the ratchet teeth so that rotation of the ratchet housing clockwise, as viewed in Figure 8, rotates the ratchet wheel 33, feed shaft 25 and feeder plates 27 clockwise, but rotation of the ratchet housing counterclockwise merely permits it to return without rotating the other parts. A link 36 connects the upper end of lever 30 and the lower portion of the ratchet housing v34.

Once each revolution of the camshaft 15, the cam 29 pushes the roller 31 and lever 30 outwardly and then allows it to return. Outward movement of this lever, acting through the link 36, ratchet housing 34, pawl 35 and 1 ratchet wheel 33, advances the feed shaft 25 and feeder plates 27 one step clockwise, as viewed in Figure 8, in this instance one eighth of a revolution. Unslit bars B heated to a working temperature are introduced singly to the radial slots 28 near the top of the plates 27 by any suitable handling mechanism not shown. Each bar thus progressively advances clockwise toward the lower part of the platesuntil it is aligned with the cutting mechanism hereinafter described.

Preferably the feed mechanism also includes means for assuring that each bar remains in the slots 28 until it is aligned with the cutting mechanism and for assuring that the feed shaft 25 does not turn too far each step. As shown in Figure 9, such means includes a plurality of upstanding guide brackets 37 fixed to the top of the bedplate and curving over the path of the bars in the feed plates. One of the brackets 37 carries a dog 38 which engages one of the radial slots 28 in the adjacent plate 27 and is held there by a spring 39. Engagement between the dog and a slot of the feed plate prevents rotation of the latter except when the feed shaft 25 is moved forcibly by the feed cam 29 on the camshaft 15. The lower portions of the brackets 37 contain aligned notches 40 which are adapted to receive each bar in succession and position it accurately with respect to the cutting mechanism. The bearings 26 in which the feed shaft 25 is mounted carry spring pressed pushers 41 which automatically move the bar into the notches 40 after the feed plates have rotated to the properposition.

guiding, cutting and eject-.

roller engages the cam.

,3 Clamping mechanism As shown in Figure 10, the clamping mechanism includes fixed and movable. jaws 50 and 51. The former is fixed to the bedplate and: has a bar receivingno'tch on its inner face aligned with brackets '37 of" the feed mechanism. The movable jaw 51' is attached to a lever 52' which is pivoted at its, lower end to the bedplate. A toggle linkage, which includes a straight link '53 and a link 54 of triangular outline, extends between the bedplate and the upper portion of lever 52.

"For operating the toggle linkage 53, 54 and thus opening and closing the jaws and 51, the camshaft 15 carries'a clamp operating cam'55 situated between itsintermediate bearings 18 and 19. A lever 56 is pivoted at its lower end to the bedplate and carries intermediate its length a roller 57, which engages the cam face of cam and functions as a cam follower. A tension. spring 58 extend s'between the upperportion of lever56 and the bedplate and thus holds the lever in a position where the The upper end of the lever carries a rocker pin 59. A spring rod 60 extends through said rocker pin and is connected to the triangularly shaped link 54 of the toggle linkage. A compression spring 61 surrounds the end portion of the spring rod outside the rocker pin 59 and bears between collars 62 and 63 on the rod.

Cam 55 has a portion 64 of enlarged radius anda portion 65 of smaller'radius. When the enlarged portion 64 of the cam engages roller-57, it pushes lever 56 out wardly from the bedplate, and acts through the toggle linkage 53, 54 to close the jaws 50 and 51. When the smaller portion 65 of the cam engages roller 57, the tension spring 58pulls the lever'56 toward thebedplate and acts through the toggle linkage to open the jaws. The cam 55 is of course coordinated with the feed cam 29, and'with the cutting mechanism hereinafter described so that the jaws are open while each bar is being fed andclosed while it is being cut.

Guiding mechanism As shown in Figures 3, 4 and 5, the crosshead 21 carries guiding mechanism, the purpose of which is to stiffen each bar as it is being cut and also to restore each bar toits original outside dimension after cutting. This guiding mechanism includes fixed and movable guidepieces' and 71; The a bar receiving notch which the guide brackets 37 of the feed mechanism. The movable guidepiece 71 is mounted on the inner end of a slide 72 which is supported for transverse movement in aslideway 73 in the crosshead 21. The outer end of the slide 72 carries a depending roller 74 (Figure-5) which rides in aguideway 75 fixed to the bedplate 10. Theguideway 75' is of an outline such that the slide 72 and the movable guidepiece 71 move toward the bar where the latter isin loose engagement therewith, except when the crosshead is retracted fully to the left, at which position the 'movable guidepiece is free of the bar. The guiding mechanism also includes a pair of rollers 76 and 77which engage the opposite sides of the bar. As the crosshead retracts or moves to the left following a cutting-operation,-the;rollers thus restore the bar to its original out side dimension.

Cutting mechanism The crosshead 21 alsocarries cutting mechanism which slits the end portion of the bar each time the crosshead moves ahead or to the right. As best shown in Figures 7 and'12, this cutting mechanism includes a transverse shaft 80= which is rotatably mounted in the-crosshead behind or totheleft of the guidingmechanism and carries a plurality of radially extending blades 81, in this instanceeight in number; These blades have cutting edges on their outer ends. -As-shown in Figures 3, 4*and5; the

the notch 40in the guide former is fixed to the crosshead 21 and has is aligned with the notches. in the fixed jaw '50 of the clamping mechanism and'in and 13, the indexing means includes a ratchet wheel 84 keyed to the blade shaft, a plate 85 mounted forfree rotation on the blade shaft, and a pawl 86 pivoted to said plate and engaging the teeth of said ratchet wheel. Alongside the crosshead 21, the bedplate 10 carries'an upstanding slotted guide 87, the front portion of the slot therein being downwardly inclined, as indicated at 88 (Figure 7). Plate 85 carries a roller 89 which rides in this slot and functions as a crank for turning the plate. As the crosshead 21 moves to the right, roller 89 moves down.

the inclined portion 88 of the slot, which acts as a. cam and turns plate 85 counterclockwise. Likewise as the crosshead moves to the left, the roller turns the plate clockwise. On one of these motions of plate 85, its pawl 86-turns'ratchet wheel 84, blade shaft 80 and blades 81 in the same direction. In this instance the blades. turn as the crosshead moves to the left and the plate 85 turns clockwise. Each time the blade shaft turns, it moves the next blade 81 to its cutting position so that in the present instance the shaft turns one eighth of a revolution each time the crosshead retracts. To prevent unintendedrotation of the blade shaft, the guide 87 carries a spring pressed dog 90 which engages the teeth of the ratchet wheel 84 (Figure 13).

Ejector mechanism The ejector mechanism removes each bar after it has been slit and the crosshead 21 retracted. Referring to Figure 11, the upper face of the bcdplate 10 has a longitudinal slot 91 through which the bars drop to a skid 92' beneath. The ejector mechanism includes a longitudinal shaft '93 which is rotatably supported on the bedplate below the top of skid 92 and carries a plurality of pusher arms 94. The upper part of the skid has slots 95 which the arms 94 can'enter for pushing bars down the'skid. The camshaftlS has a crank 96 which is connected to one of the pusher arms by a connecting rod 97. On each revolution of the-camshaft the pusher arms 94 move into the slots 95 and push the bars down the skid92. Preferably the lower end of the skid carries a releasable stop 98 for holding bars on the skid until it is desired to remove them.

Operation 7 The operationof the bar slitting machine and theslitas foliows:

The crankshaft 12 and the camshaft 15 are driven at,

identical speeds and the machine slits one bar 13 for each revolution of these shafts. Each bar previously is heated toa working temperature and is introduced singly to-tl'ie slots 28 at the top of the feeder plates 27, which-there: upon advance each bar one step per revolution of the camshaft. The bar advances in this fashion until-it arrives at the position in which it is to be clamped for cutting. Thereupon the camshaft closes the movable jaw-51; of the clamping mechanism on the bar and securely holds it against the fixed jaw 50.

The crosshead 21 advances and retracts during each revolntion'of the crankshaft. The camshaft and crankshaft are timed so that the crosshead advances during the period while the clamp jaws 5t) and 51 are closed, and further so that the bar feeds while these jaws are open. As'thecrossheadadvances, the guide pieces 70 and 71 close on the bar and stiffen it, and one of the blades 81 cuts aslit in the end portion of the bar. As the crosshead retracts, the rollers 76 and 77 restore the bar to its original outside dimension, with the jaws 50 and 51 still closed. Also the blade shaft indexes to move a cooled blade to the cutting position. Since each blade makes only one cut out of eight, there is ample time for each blade to cool before it makes another cut.

Next the jaws 50 and 51 release the bar and it drops through the slot 91 on to skid 92. Each revolution of the camshaft the pusher arms 94 shove the bars down the skid. The bars remain on the skid long enough to cool and then they are discharged by retraction of stop 98.

From the foregoing description it is seen that the present invention affords a simple method and machine for automatically and rapidly slitting the end portions of a bar in a continuous operation. The feature of indexing the blades with each cut is particularly advantageous, as it assures that each blade cools before making another cut. This arrangement is preferable to a disc-type cutter inasmuch as there is less heat conduction between adjacent cutting edges.

While one embodiment of my invention has been shown and described it Will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A bar slitting machine comprising a bedplate, clamping mechanism on said bedplate for holding a bar in a fixed position, a reciprocable crosshead supported on said bedplate, a plurality of radially directed blades rotatably supported on said crosshead, one of said blades being positioned to slit the end of a bar held by said clamping mechanism on movement of said crosshead toward the bar, a crank carried on said crosshead, a guide for said crank carried on said bedplate, said guide having a cam portion engageable with said crank for turning the latter on reciprocation of said crosshead, a pawl and ratchet mechanism connecting said crank and said blades for indexing said blades as said crank turns to move a different blade to a position for slitting a bar, and drive means on said bedplate for reciprocating said crosshead.

2. A bar slitting machine comprising a bedplate, clamping mechanism on said bedplate for holding a bar in a fixed position, a reciprocable crosshead supported on said bedplate, a shaft rotatably supported in said crosshead and carrying a plurality of radially extending blades, one of said blades being positioned to slit the end of a bar held by said clamping mechanism on movement of said crosshead toward the bar, pawl and ratchet means connected with said shaft, a cam and cooperating crank connected respectively to said bedplate and said pawl and ratchet, means for turning said shaft through said pawl and ratchet means on movement of said crosshead in one direction, such turning of the shaft moving a diflferent one of said blades to a position for slitting a bar, a crankshaft rotatably supported on said bedplate, and a connecting rod between said crankshaft and said crosshead.

3. A bar slitting machine comprising a bedplate, clamping mechanism on said bedplate for holding a bar in a fixed position, a reciprocable crosshead supported on said bedplate, a shaft rotatably supported in said crosshead and carrying a plurality of radially extending blades having cutting edges on their outer ends, one of said blades being positioned to slit the end of a bar held by said clamping mechanism on movement of said crosshead toward the bar, pawl and ratchet means connected with said shaft and carrying a crank, a guide on said bedplate having a cam portion engageabie with said crank, reciprocation of said crosshead moving said crank in said guide and movement in one directi:n turning said shaft through said pawl and ratchet means for moving a different one of said blades to a position for slitting a bar, a crankshaft rotatably supported on said bedplate, and a connecting rod between said crankshaft and said crosshead.

A bar slitting machine comprising a bedplate, clamping mechanism on said bedplate for holding a bar in a fixed position, a reciprocable crosshead supported on said bedplate, a shaft rotatably supported in said crosshead and carrying a plurality of radially extending blades having cutting edges on their outer ends, one of said blades being positioned to slit the end of a bar held by said clamping mechanism on movement of said crosshead toward the bar, pawl and ratchet means connected with said shaft and carrying a crank, a guide on said bedplate in which said crank rides and having an inclined portion, reciprocation of said crosshead moving said crank within said guide and movement thereof in one direction within said inclined portion turning said shaft through said pawl and ratchet means for moving a different one said blades to a position for slitting a bar, a crankshaft rotatably supported on said bedplate, a connecting rod between said crankshaft and said crosshead, and means coordinated with said crankshaft for opening and closing said clamping mechanism.

5. A bar slitting machine comprising a bedplate, a crankshaft and a camshaft journaled to said bedplate and geared together to rotate at similar speeds, a bar feeding mechanism on said bedplate, a feed cam on said camshaft operatively connected with said feeding mechanism, a bar clamping mechanism on said bedplate, a clamp operating cam on said camshaft operatively connected with said clamping mechanism, said cams being related to operate the feeding mechanism while the clamping mechanism is released, a crosshead supported for reciprocable movement on said bedplate and operatively connected with said crankshaft, cutting mechanism on said crosshead for slitting the end portion of a bar held by said clamping mechanism on movement of said crosshead toward the bar, means on said crosshead for stiffening the bar during slitting, and rollers on said crosshead engageabie with the outside of the bar for restoring its outside dimensions on retraction of said crosshead after slitting.

6. A machine as defined in claim 5 in which said bedplate has an opening through which bars can drop when released by said clamping mechanism.

References Cited in the file of this patent UNITED STATES PATENTS 240,538 Powers Apr. 26, 1881 376,914 Russell Jan. 24, 1888 389,239 Myers Sept. 11, 1888 574,162 Prentice Dec. 29, 1896 671,431 Baker Apr. 9, 1901 716,030 Goetsche Dec. 16, 1902 1,147,993 Wilcox et al July 27, 1915 1,546,914 Calkins July 21, 1925 1,893,509 Stimpson Jan. 10, 1933 2,298,077 Witter Oct. 6, 1942 2,575,504 Wright Nov. 20, 1951 2,621,937 Hunziker Dec. 16, 1952 

